5-FAM (5-Carboxyfluorescein) 是一种绿色荧光探针，用于标记肽、蛋白质和核苷酸，激发/发射波长为 490 nm/520 nm。

6-FAM contains a carboxylic acid that can be used to react with primary amines via carbodiimide activation of the carboxylic acid.

6-FITC, a derivative of fluorescein, is generally used in flow cytometry.

Fluorescein-5-maleimide is a fluorescent thiol-reactive dye used to conjugate fluorescein to proteins (excitation: 494 nm, emission: 519 nm).

6-Aminofluorescein is a building block for synthesis of fluorescein and a reagent for fluorescence studies.

5-FAM SE is a single isomer, one of the most popular green fluorescent reagents used for labeling peptides, proteins and nucleotides.